/***************************************************************************/
/*                                                                         */
/*  gxvprop.c                                                              */
/*                                                                         */
/*    TrueTypeGX/AAT prop table validation (body).                         */
/*                                                                         */
/*  Copyright 2004, 2005 by suzuki toshiya, Masatake YAMATO, Red Hat K.K., */
/*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
/*                                                                         */
/*  This file is part of the FreeType project, and may only be used,       */
/*  modified, and distributed under the terms of the FreeType project      */
/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
/*  this file you indicate that you have read the license and              */
/*  understand and accept it fully.                                        */
/*                                                                         */
/***************************************************************************/

/***************************************************************************/
/*                                                                         */
/* gxvalid is derived from both gxlayout module and otvalid module.        */
/* Development of gxlayout is supported by the Information-technology      */
/* Promotion Agency(IPA), Japan.                                           */
/*                                                                         */
/***************************************************************************/


#include "gxvalid.h"
#include "gxvcommn.h"


/*************************************************************************/
/*                                                                       */
/* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
/* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
/* messages during execution.                                            */
/*                                                                       */
#undef  FT_COMPONENT
#define FT_COMPONENT trace_gxvprop


/*************************************************************************/
/*************************************************************************/
/*****                                                               *****/
/*****                      Data and Types                           *****/
/*****                                                               *****/
/*************************************************************************/
/*************************************************************************/

#define GXV_PROP_HEADER_SIZE (4 + 2 + 2)
#define GXV_PROP_SIZE_MIN GXV_PROP_HEADER_SIZE

typedef struct  GXV_prop_DataRec_
{
    FT_Fixed version;

} GXV_prop_DataRec, * GXV_prop_Data;

#define GXV_PROP_DATA(field)  GXV_TABLE_DATA(prop, field)

#define GXV_PROP_FLOATER 0x8000U
#define GXV_PROP_USE_COMPLEMENTARY_BRACKET 0x1000U
#define GXV_PROP_COMPLEMENTARY_BRACKET_OFFSET 0x0F00U
#define GXV_PROP_ATTACHING_TO_RIGHT 0x0080U
#define GXV_PROP_RESERVED 0x0060U
#define GXV_PROP_DIRECTIONALITY_CLASS 0x001FU


/*************************************************************************/
/*************************************************************************/
/*****                                                               *****/
/*****                      UTILITY FUNCTIONS                        *****/
/*****                                                               *****/
/*************************************************************************/
/*************************************************************************/

static void
gxv_prop_zero_advance_validate(FT_UShort gid,
                               GXV_Validator valid)
{
    FT_Face face;
    FT_Error error;
    FT_GlyphSlot glyph;


    GXV_NAME_ENTER("zero advance");

    face = valid->face;

    error = FT_Load_Glyph(face,
                          gid,
                          FT_LOAD_IGNORE_TRANSFORM);
    if (error)
        FT_INVALID_GLYPH_ID;

    glyph = face->glyph;

    if (glyph->advance.x != (FT_Pos)0 ||
        glyph->advance.y != (FT_Pos)0)
        FT_INVALID_DATA;

    GXV_EXIT;
}


/* Pass 0 as GLYPH to check the default property */
static void
gxv_prop_property_validate(FT_UShort property,
                           FT_UShort glyph,
                           GXV_Validator valid)
{
    if (glyph != 0 && (property & GXV_PROP_FLOATER))
        gxv_prop_zero_advance_validate(glyph, valid);

    if (property & GXV_PROP_USE_COMPLEMENTARY_BRACKET)
    {
        FT_UShort offset;
        char complement;


        offset = (FT_UShort)(property & GXV_PROP_COMPLEMENTARY_BRACKET_OFFSET);
        if (offset == 0)
            FT_INVALID_DATA;

        complement = (char)(offset >> 8);
        if (complement & 0x08)
        {
            /* Top bit is set: negative */

            /* Calculate the absolute offset */
            complement = (char)((complement & 0x07) + 1);

            /* The gid for complement must be greater than 0 */
            if (glyph <= complement)
                FT_INVALID_DATA;
        }
        else
        {
            /* The gid for complement must be the face. */
            gxv_glyphid_validate((FT_UShort)(glyph + complement), valid);
        }
    }
    else
    {
        if (property & GXV_PROP_COMPLEMENTARY_BRACKET_OFFSET)
            GXV_TRACE(("glyph %d cannot have complementary bracketing\n",
                       glyph));
    }

    /* this is introduced in version 2.0 */
    if (property & GXV_PROP_ATTACHING_TO_RIGHT)
    {
        if (GXV_PROP_DATA(version) == 0x00010000UL)
            FT_INVALID_DATA;
    }

    if (property & GXV_PROP_RESERVED)
        FT_INVALID_DATA;

    if ((property & GXV_PROP_DIRECTIONALITY_CLASS) > 11)
    {
        /* TODO: Too restricted. Use the validation level. */
        if (GXV_PROP_DATA(version) == 0x00010000UL ||
            GXV_PROP_DATA(version) == 0x00020000UL)
            FT_INVALID_DATA;
    }
}


static void
gxv_prop_LookupValue_validate(FT_UShort glyph,
                              GXV_LookupValueCPtr value_p,
                              GXV_Validator valid)
{
    gxv_prop_property_validate(value_p->u, glyph, valid);
}


/*
 +===============+ --------+
 | lookup header |         |
 +===============+         |
 | BinSrchHeader |         |
 +===============+         |
 | lastGlyph[0]  |         |
 +---------------+         |
 | firstGlyph[0] |         |    head of lookup table
 +---------------+         |             +
 | offset[0]     |    ->   |          offset            [byte]
 +===============+         |             +
 | lastGlyph[1]  |         | (glyphID - firstGlyph) * 2 [byte]
 +---------------+         |
 | firstGlyph[1] |         |
 +---------------+         |
 | offset[1]     |         |
 +===============+         |
 |
   ...                      |
 |
   16bit value array         |
 +===============+         |
 |     value     | <-------+
   ...
 */

static GXV_LookupValueDesc
gxv_prop_LookupFmt4_transit(FT_UShort relative_gindex,
                            GXV_LookupValueCPtr base_value_p,
                            FT_Bytes lookuptbl_limit,
                            GXV_Validator valid)
{
    FT_Bytes p;
    FT_Bytes limit;
    FT_UShort offset;
    GXV_LookupValueDesc value;

    /* XXX: check range? */
    offset = (FT_UShort)(base_value_p->u +
                         relative_gindex * sizeof(FT_UShort));
    p = valid->lookuptbl_head + offset;
    limit = lookuptbl_limit;

    GXV_LIMIT_CHECK(2);
    value.u = FT_NEXT_USHORT(p);

    return value;
}


/*************************************************************************/
/*************************************************************************/
/*****                                                               *****/
/*****                         prop TABLE                            *****/
/*****                                                               *****/
/*************************************************************************/
/*************************************************************************/

FT_LOCAL_DEF(void)
gxv_prop_validate(FT_Bytes table,
                  FT_Face face,
                  FT_Validator ftvalid)
{
    FT_Bytes p = table;
    FT_Bytes limit = 0;
    GXV_ValidatorRec validrec;
    GXV_Validator valid = &validrec;

    GXV_prop_DataRec proprec;
    GXV_prop_Data prop = &proprec;

    FT_Fixed version;
    FT_UShort format;
    FT_UShort defaultProp;


    valid->root = ftvalid;
    valid->table_data = prop;
    valid->face = face;

    FT_TRACE3(("validating `prop' table\n"));
    GXV_INIT;

    GXV_LIMIT_CHECK(4 + 2 + 2);
    version = FT_NEXT_ULONG(p);
    format = FT_NEXT_USHORT(p);
    defaultProp = FT_NEXT_USHORT(p);

    /* only versions 1.0, 2.0, 3.0 are defined (1996) */
    if (version != 0x00010000UL &&
        version != 0x00020000UL &&
        version != 0x00030000UL)
        FT_INVALID_FORMAT;


    /* only formats 0x0000, 0x0001 are defined (1996) */
    if (format > 1)
        FT_INVALID_FORMAT;

    gxv_prop_property_validate(defaultProp, 0, valid);

    if (format == 0)
    {
        FT_TRACE3(("(format 0, no per-glyph properties, "
                   "remaining %d bytes are skipped)", limit - p));
        goto Exit;
    }

    /* format == 1 */
    GXV_PROP_DATA(version) = version;

    valid->lookupval_sign = GXV_LOOKUPVALUE_UNSIGNED;
    valid->lookupval_func = gxv_prop_LookupValue_validate;
    valid->lookupfmt4_trans = gxv_prop_LookupFmt4_transit;

    gxv_LookupTable_validate(p, limit, valid);

Exit:
    FT_TRACE4(("\n"));
}


/* END */